This research is concerned with four aspects of the behavioral neuroscience of ingestive behavior: the chemical controls of 1) thirst, and 2) sodium appetite, 3) the chemical controls of food satiety, and 4) the ontogeny of ingestive behavior. The contribution made by angiotensin to spontaneous drinking is being studied in rats that are allowed to feed and drink freely while angiotensin synthesis and receptor action are blocked. The mechanism by which the hormone makes the brain thirsty for water (its dipsogenic effect), and how, in synergy with mineralocorticoids, it produces an appetite for salty solutions is being studied. The subfornical organ (SFO) has been shown to be essential for the dipsogenic effect of blood-borne angiotensin. We will now explore the brain for the site of the receptors that may also mediate the dipsogenic effect but in response to angiotensin of cerebral origin. The role of the SFO in the sodium appetite induced by angiotensin especially in synergy with mineralocorticoids is also being studied. The chemical controls of food intake are being studied with physiological doses of catecholamines which delay satiety when they are infused into the anterior forebrain. Our aim is to understand the possible adrenergic mechanisms for arousal and suppression of the brain mechanisms of meal taking. The ontogeny of feeding and drinking is being studied in newborn rats in order to describe the chronology of the development of the separate controls of each mode of ingestion and the manner in which they are assembled into adult feeding and drinking. We are describing the calendar of the onset of responsiveness of the infant brain to the chemical agents that arouse feeding and drinking in the adult, and the means by which the newborn controls its intake both while sucking mother's milk and while ingesting fluids (food and water) in isolation from her.